<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <style>
        /* Style for the animated round div */
        .animated-round-div {
            width: 100px;
            height: 100px;
            background-color: #27ae60; /* Emerald Green */
            border-radius: 50%;
            margin: 50px;
            animation: rotateAndScale 3s infinite alternate;
        }

        /* Keyframe animation for rotating and changing size */
        @keyframes rotateAndScale {
            0% {
                transform: rotate(0deg) scale(1);
            }
            50% {
                transform: rotate(180deg) scale(1.2);
            }
            100% {
                transform: rotate(360deg) scale(1);
            }
        }
    </style>
</head>
<body>
<div class="animated-round-div"></div>
</body>
</html>
